Lubrication of internal combustion engines



April 4, 1944. E. D. JONES ET AL LUBRICATION OF INTERNAL COMBUSTIONENGINES Filed March 20, 1942 Jnuenlor Emoqy 1). Jones Louis MHuP/ahyat'm ua/whoa);

0 Ho meg Patented Apr. 4, 1944 LUBRICATION OF INTERNAL COMBUSTIONENGINES Emory D. Jones and Louis N. Murphy. Detroit, Mich.

Application March 20, 1942, Serial No. 435,512

Claims.

This invention relates to lubrication of internal combustion engines andparticularly to provisions for diluting engine lubricating oil under lowtemperature conditions to 'i-acilitate starting.

Since viscosity of oils varies inversely as their temperatures, itfollows that a viscosity well suited to operating temperature of anengine may be undesirably heavy for starting the engine cold. In mildweather, the viscosity at starting or atmospheric temperature is notcommonly sufficiently great to be a material detriment, but in coldweather and particularly under conditions of severe cold, consequentundue viscosity tends to seriously interfere with starting.

In the case of Diesel engines, undue lubricant viscosity at starting isespecially objectionable since such engines require much greatercranking power and speed than engines using relatively low compression,and hence require good starting lubrication more urgently than otherinternal combustion types.

The problem :abovediscussed has beenmitigated in a crude way by pouringmore or less gasoline into the crank case to dilute the lubricant incold weather, but there has been no assurance that such dilution wasneither inadequate nor extreme and no convenient means for accomplishingsuch dilution.

An object of the invention is to provide a convenient and permanentapparatus for introducing a diluting liquid into an engine crank case,as re quired.

A further object is to provide for accurately measuring the quantity ofliquid employed for dilution.

A further object is to subject the dilution system to a thermostaticcontrol such as will automatically prevent use of the system when theweather is sufficiently moderate to obviate necessity for dilution.

A further object is to provide for an indication of crank casetemperature to assist in calculating the amount of diluent employed withproper regard to viscosity of the lubricant.

A further object is to thoroughly safeguard such a dilution systemagainst danger of leakage or tampering, since excessive gasoline in thecrank-case involves a serious risk of explosion and fire.

These and various other objects are attained by the constructionhereinafter described and illustrated in the accompanying drawing,wherein:

Fig. 1 is a diagrammatic view of the improved system applied to aninternal combustion engine which may be considered as illustrative ofeither an ordinary gasoline or Diesel type of engine.

Fig. 2 is a front view of a time switch for controlling a. circuit forenergizing a pump.

Fig. 3 is a front view of a temperature indidicator employed in thesystem.

In these views, the reference character I designates an internalcombustion engine whereof the crank case 2 constitutes a reservoir forlubricating oil as is common practice. For supplying gasoline or somediluting liquid to said engine there is provided the usual fuel tank 3from which a supply line 4 leads to the engine and includes the usualpump 5, particularly indispensable in Diesel engines. From the line 4branches a. pipe connection 6 to the crank case and in such connectionis interposed an electrically driven pump 1 of a type quite positivelyobstructing flow when idle. Further said pump is of a type to effect avery steady flow at a quite gradual rate as for example 20 fluid ouncesper minute. Any small valved reciprocatory pump would serve the purposeas for example that marketed under the name Autopu1se."

The motor energizing the pump 1 derives current from the engine battery.8, corresponding terminals of the battery and motor being grounded asindicated respectively at 9 :and Ill. The other battery and motorterminals are connected by a conductor H controlled by switches l2, l3,l4 and I5.

The switch I2 is of the semi-automatic type known as a time switch andserves to effect closure of the circuit for a selective short timeperiod. Thus said switch comprises a rotary pointer i6 travelling a dialgraduated in suitable time units and adapted to close the circuit whenset at any point other than zero and to open the circuit on expirationof the time indicated by such setting. As illustrated (Fig. 2), saiddial is graduated for a maximum flow of five minutes, it beingunderstood however that a considerably shorter flow period willordinarily suffice. The switch I3 is thermostatic, being adapted toautomatically break the circuit when the weather is sufliciently mild torender dilution of the lubricant superfluous. The temperature at whichthe switch i3 is adapted to take effect depends primarily on the typeand characteristics of the engine to which the dilution system isapplied and further depends on the degree of viscosity of the lubricant.The switches l4 and I5 are both safety switches such as are commonlyused to control an ignition circuit of a motor vehicle. Provision ofthese two switches serves to thoroughly safeguard the system againsttampering. Ignition circuit not shown" will be controlled additionallyby one of these two switches.

Since the tour described switches are well known as regards theiroperating mechanism a diagrammatic showing thereof suflices.

Since the diluent employed will be much more volatile than thelubricant, it will largely be evaporated in the course of a days run ofthe engine, the amount of evaporation depending on the temperature atwhich the engine is operated. If the maximum crank case temperatureattained in course of a day's run is known, this may serve as basis ofan approximation as to diluent evaporation and will assist the operatorin determining proper quantity of diluent to add on completion of theday's run. It is desirable to add diluent before the engine has cooledsince it will form a homogeneous mixture with warm oil but not with oilat low starting temperature.

For indicating the maximum temperature attained in a day's run there isprovided an indicator I? connected by a tube 18 to a pressurestat l9permanently inserted in the crank case and subject to the lubricanttemperature. The indicator H has a pointer 20 which is shiftedproportionately to the pressure transmitted through the tube, suchpressure being determined by crank case temperature. Since the pointer20 responds only to increasing pressure, it serves to indicate themaximum temperature attained in a day's run. Said pointer may, however,be reset at its zero position preliminary to each day's run. Preferablythe indicator H is equipped with a second pointer 2| adapted to advanceor recede to indicate instantaneous crank case temperatures. Theinstrument described is of standard type and hence the diagrammaticshowing thereof afforded by the drawing suiflces.

The described dilution system provides for an accurate and adequatedilution of crank case lubricant when needed, without wasteful excessand eliminates the considerable risk entailed by excessive dilution.Said system may be advantageously applied to any vehicle driven by aninternal combustion engine and required to operate under atmospherictemperature conditions in entailing starting dimculties due to excessiveViscosity of the lubricant.

What we claim is:

1. In a lubricant dilution system for internal combustion engines, thecombination with the lubricant-receiving crank case of an internalcombustion engine, 01' a tank holding a diluting liquid, a delivery lineleading from said tank to the crank case, a pump inducing flow in saidline, and control means for the pump for predetermining a selectiveperiod of operation of the pump, including an adjustable element foraccurately setting the selected period, said pump positively prohibitingflow when idle.

2. In a lubricant dilution system for internal combustion engines, asset forth in claim 1, thermostatic means for rendering said controlmeans ineflective at temperatures in excess of a predetermined range.

3. In a lubricant dilution system for internal combustion engines, thecombination with the lubricant-receiving crank case of an internalcombustion engine, of a tank holding a diluting liquid, a delivery lineleading from said tank to the crank case, an electrically-driven pumpfor inducing flow in said line, a circuit controlling said pump, and atime switch controlling said circuit, adapted to open upon apredetermined time lapse, said pump positively prohibiting flow whenidle,

4. In a lubricant dilution system for internal combustion engines, asset forth in claim 3, a thermostatic switch controlling said circuit andadapted to open at a. predetermined temperature.

5. In a lubricant dilution system for internal combustion engines, thecombination with the lubricant-receiving crank case of an internalcombustion engine, of a tank holding a diluting liquid, a delivery linefrom said tank to the crank case, an electrical device controlling theflow in said line, a circuit for said electrical device, and a timeswitch controlling said electrical device, adapted to open upon apredetermined time lapse, said electrical device positively prohibitingflow in said delivery line when deenergized.

EMORY D. JONES. LOUIS N. MURPHY.

